Compounds of Formula I, below
including bicifadine, and salts and other forms of these compounds, are analgesics that are not narcotics (that is, are not morphine-like in action). See U.S. Pat. No. 4,231,935 and U.S. Pat. No. 4,196,120.
In administering a compound of Formula I to produce analgesia, it is important that the compound be administered in an effective manner to provide prompt and sustained activity through the presence of the compound in the blood system to effectively alleviate pain in the patient. There remains a significant, unmet need in the art for effective compositions and methods for delivering a compound of Formula I that will provide rapid relief of moderate and severe pain when administered and will maintain this relief for long periods of time.